You are absolutely right about this: she has every right to simply cancel any purchase made over the Internet within two weeks without giving any reason whatsoever. It's the law, and it's totally on her side in this case. She also does not need a lawyer or anything. She just needs to tell them she wants to cancel. Perhaps she'll have to do it via snail mail, but that depends. E-Mail should do, given it's apparently a web shop.

... these.

OMeta: http://www.cs.ucla.edu/~awarth/ometa/
The more recent OMeta 2.0: http://jarrett.cs.ucla.edu/ometa-js/
And, of course, COLA - http://piumarta.com/software/cola/

Self-sustainment, anyone? ;-)
One more link: http://www.swa.hpi.uni-potsdam.de/s3/